On Extended Regular Expressions

d abstract) Benjamin Carle, Paliath Narendran and Colin Scheriff Dept. of Computer Science University at Albany–SUNY Albany, NY 12222 June 19, 2007 In this paper we extend the work of Campeanu, Salomaa and Yu [3] on extended regular expressions featured in the Unix utility egrep and the popular scripting language Perl. We settle the open issue of closure under intersection and provide an improved pumping lemma that will show that a larger class of languages is not recognizable by extended regular expressions.

• Type: Conference
• Year: 2009
• Where: LATA
• Authors: Benjamin Carle, Paliath Narendran
• Keywords: Automata Theory, Colin Scheriff Dept, LATA 2009, Regular Expressions, Unix Utility Egrep